People are building tools that will do their own pull off the mid-level API (rather than the “streaming” API that the regular search function uses), but even then you’re only getting 10% of the possible tweets unless you pay the big fees associated with “firehose” access. The regular search will give you a great indication of what the most important/visible/popular tweets are for your search, but if you’re trying to make a case that you’re getting representative or comprehensive results, it doesn’t seem to be adequate. (All of this caveated that I don’t actually know what I’m talking about here, just repeating what I’ve been told.)
Mike is dropping science about Twitter’s illusion of comprehensiveness, but yeah, the search results are definitely lacking. The other night when I was using the search function on the official iPhone app to go through #princemenu I was not getting a lot of the Tweets that were in my stream. (Echofon’s results were slightly better, but not by much.)
This practice and especially its lack of transparency is pretty gross and sinister, filtering as it does information out from “untrusted” sources—just think about the ramifications of that practice being applied to, say, political dissent of even the mildest sort, or opinions that might not hew to the geek-bro-tastic mainstream that is so self-reinforcedly popular online. (And yes, I know that unfiltered results bring up a lot of spambots, but what can you do.) But I also am fully aware that Twitter’s business model as it currently stands is very dependent on it turning into a broadcast medium, one where it can beam out official messages from Important People and, even more crucially, Important Brands. Once the bubble pops this might be a little less of an issue. But right now there’s too much money and hope tied up in the idea of social media, particularly directed social media in which people think they are using free will to find things but are actually being covertly steered in particular directions and toward particular people, to think that it won’t get worse before it gets better.